The 'Without You' singer is said to be Simon Cowell's first choice to replace Nicole Scherzinger and Paula Abdul, who were yesterday (January 31) confirmed to be leaving the Fox show.
Carey was heavily rumoured to be judging The X Factor before its first season launched last summer and had been due to accompany Cowell at the Judges' Houses stage, but was unable to travel following the arrival of Hurricane Irene.
"Simon wants nothing but the best for The X Factor - and Mariah is the best," a show insider told The Mirror.
However, Carey's husband Nick Cannon has already dismissed suggestions that she will join The X Factor, telling reporters recently that such a move would be a "step down".
"Why would my wife want to be on a show like that?" he said. "For somebody who has a legendary career, I don't know why they would."
Cowell previously said that he was determined to find a role on The X Factor USA for Carey, adding: "I'm a huge fan of hers, not just as an artist, but as a person, and I love her to death."
Abdul and Scherzinger also backed Carey for a potential X Factor role in August.
> Steve Jones: 'I'm not hosting X Factor USA season two'